The Singapore Land Transport Authority (LTA) is considering options for the alignment of the 50km Cross Island Line (CRL).

LTA will launch a tender for site investigations (SI) to study each option of the mass rapid transit (MRT) line, with work to begin in Q4 of this year. Investigation works have already commenced for the 9km skirting alignment option, which started last month.

The direct alignment is 4km long, with 2km of the tunnel running beneath the Central Catchment Nature Reserve (CCNR).

Findings of the investigations provides LTA with information on the underground soil conditions and input for phase II of the Environmental Impact Assessment (EIA), which will assess the impact of construction and operations.

"The direct alignment is 4km long, with 2km of the tunnel running beneath the Central Catchment Nature Reserve (CCNR)."

LTA’s CEO Chew Men Leong said: "LTA understands the sensitivity of the SI construction, and will work with NParks and the nature groups closely to ensure that all mitigating measures are rigorously implemented.

"The Government has not yet decided which alignment to take for the CRL. We will continue to study both possible alignments objectively, taking into consideration all factors. Concerns of all stakeholders and the findings from the SI works will help the government make an informed and considered decision."

The CRL has more than 30 stations and will start from Changi, passing through Loyang, Pasir Ris, Hougang, Ang Mo Kio, Bukit Timah, Clementi, West Coast, and Jurong. It is scheduled to be completed by 2030.

Expected to be used by at least 600,000 commuters every day, CRL will connect all of the existing radial MRT lines with nearly half of its stations being interchange stations.